35 



rine. Spores and Th. as in Collema, except that the cortical layer 

 is distinctly parenchymatous. A large genus. 21 spp. and 4 sub- 

 spp. 



Genus 30. Hydrothyhia. Apotb. biatorine. Spores 4 loc, 

 colorless. Th. foliaceous, veiny beneath. Cortical layer parenchy- 

 matous ; gonimia concatenate. A genus of one sp. occurring in 

 cold streams of N. E. and California. 



Fam. 7. Lecanohei. Thallus erustaceous ; now lobulate or even 

 branched, but mostly uniform ; adnate ; hypothallus indistinct. 



Subfam. 1. Edlecanoeei. Apoth. scutellseform. 



G-enus 31. I^lacodium. Apoth. now zeorine ; or biatorine. 

 Spores rarely simple, or bilocular, commonly polar-bilocular, color- 

 less. Th. now lobulate, or rarely fruticulose, mostly uniform and 

 oftener yellowish. A large genus. 27 spp. and 1 subspp. 



Genus 32. Lecanora. Apoth. now zeorine. Spores simple, or 

 2-4 loc, or long-fusiform and pluriloc, colorless. Th. now lobu- 

 late, rarely fruticulose, mostly uniform. A very large genus. 45 

 spp. and 10 subspp. 



Genus 33. Rinodina. Apoth. scutellseform, more often zeorine ; 

 now lecideine. Hypothecium mostly colorless. Spores 2, rarely 4 

 loc, brown. Th. erustaceous ; in a few spp. lobed at the circum- 

 ference, but mostly uniform. A large genus. 16 spp. 



Subfam. 2. Peetusariei. Apoth. typically compound and dif- 

 form, but reverting to the scutellseform type. 



Genus 34. Peetusaria. Apoth. globular-difform, opening by 

 pores, and including one to several nucleiform hymenia ; but now 

 expla'nate and Leeanorine. Spores simple or 2 loc, colorless, mostly 

 very large. A large genus. 15 spp. 



Genus 35. Phltctis. Apoth. erumpent, rounded-difform, at 

 length somewhat dilated, the blackening disk veiled by the thallus. 

 Spores muriform, brown or decelerate. Th. uniform. A small 

 genus, of which one sp. occurs, according to Krempelhuber, in 

 Texas, and another has been found in Oregon. 



Subfam. 3. Ueceolariei. Apoth. more or less urceolate. 



Genus 36. Conotrema. Apoth. urceolate, truncate-conoid ; a 

 black proper exciple, veiled by an evanescent thalline one. Spores 

 cylindraceous, very long, multilocular, colorless. Thallus uniform. 

 A genus of one sp. on the Atlantic coast. 



Genus 37. Gyalecta. Apoth. urceolate-biatorine, with a some- 



